1974 FJ40 - Thoughts on Ironman 4x4 spring kit

[Ironman4x4America]

The Foam Cell Pro shocks are designed for 4x4 touring, meant to be simple, reliable, and reasonably priced. They were originally designed for military use on up-armored Land Cruisers and Hiluxes for NATO and JSOC.

If your 40 is living the retired life then yes they are overkill as you will never work them hard enough Sunday driving to appreciate the benefit of a big bore shock. They still will work great, just overkill. But if you are taking the 'ol girl out on trails with some weight and getting after it then the FCP's will really show their full benefits. Hope this helps!

-Miller

 

[Ironman4x4America]

Is the front leaf spring pin offset/ if you flip the springs will it center the shock? Also, what are the part numbers for that U-bolt kit?

The 40 Series U-bolt kit is SKU: 415UBK and you will need 4 of them to complete both front and rear axels. Holler if you have any other questions.

-Miller

 

[Ironman4x4America]

I also wanted to provide some reference specs for our 40 Series leaf springs along with some tips to make the ride better. See below images of the TOY001B front leaf pack, and TOY002B rear leaf pack.

These are both Single Stage Leaf Springs with a 7 stack of individual springs. These leaf springs are looking for some added weight to be on them with the 7 stack. They are considered a medium load spring looking for to an additional load of 0-220lbs for the front and 0-440lbs for the rear. These will work with both the F Series and B Series engines, although the 2F and 3B engines are a bit heavier, that weight will help. The TOY001B and TOY002B are for the 1960-'80 40 Series. The TOY001B front leaf is also for the 45 Series and for the 1980-'84 42 Series. All other 40 Series in the longer wheel bases will use other part numbers front and rear.

If your 40 is bone stock, no added weight from any accessories, no front winch, just a stock Sunday cruiser, then I would highly recommend removing a leaf from the stacks front and rear for a better ride. Typically the #3 leaf is a good one to start with. Without any additional weight, they will be firm and sit a bit too tall, but again, simply remove a leaf to bring it back down a bit.

My recommended process is to get measurements before and after the suspension install. This data will help you dial in how the vehicle sits.

First, get your Land Cruiser on dead level ground on the current suspension setup and measure from the center of each hub straight up to the bottom edge of each fender. Do this for all 4 corners and record the data.

Second, do your suspension install as the components were sent, don't remove any leafs yet. Once installed, drive the vehicle around the block a bit, hit a bump or two, so everything settles in. Take note how it feels while driving, how it sits, how it reacts, how it handles, etc... Then get back on dead level ground and do the same measurements again. Record the data.

Now, compare the before and after measurements to see how much the vehicle changed, what the rake is (fore and aft), what the list is. You now have numbers you can use to make smart and specific suspension adjustments, like removing leafs. If you do end up removing a leaf go through the same measurement exercise again to see how much did it change, repeat and adjust as necessary.

I do this process every time I fart around with the suspension, and more importantly, every time I add or remove significant weight from the vehicle. This is best when adding/removing permanent accessories like bumpers, winches, etc... It's really smart to see how much the added or subtracted weight changes how the vehicle sits. Follow this process and the data will help you make better decisions for suspension adjustments resulting in a better ride, better weight support, and a better handling safer driving vehicle.

And if you have any other curveballs like an Aqualu alloy tub, Metaltech roll cage, aftermarket tube fenders, run it without the OEM roof, etc... or other mods that affect the axel weights then take that into consideration and rely on the measurement process to adjust suspension.

Again, typically if its a stock "Sunday Cruiser" then you will want to remove a leaf.

I love a good process! It's good to build the discipline to follow and refine a process.

I hope this novel helps! Holler if you have any other questions!

-Miller

 

[Ride Fly]

The Foam Cell Pro shocks are designed for 4x4 touring, meant to be simple, reliable, and reasonably priced. They were originally designed for military use on up-armored Land Cruisers and Hiluxes for NATO and JSOC.

If your 40 is living the retired life then yes they are overkill as you will never work them hard enough Sunday driving to appreciate the benefit of a big bore shock. They still will work great, just overkill. But if you are taking the 'ol girl out on trails with some weight and getting after it then the FCP's will really show their full benefits. Hope this helps!

-Miller

Thanks Miller! That's great to hear directly from actual suppliers and manufacturers of products we members use! That said, can you tell me more details on some of the reports of your '40 springs being too short? I asked one of your CS guys and he thought it was because the '40 was one of the most heavily modified vehicles and the hangar/shackle placements aren't always uniformly spaced. I asked him if he could tell me the measurements of the springs but couldn't actually measure them either because he was not collocated with the factory.

I'd like to know the virtual eye-to-eye distance (flat distance as the spring sits on the ground on its two eyelets) and the actual curved distance along the length of the spring. If I knew those measurements, I'd have an idea if they would be long enough. Thanks again Miller!

 

[Ironman4x4America]

Thanks Miller! That's great to hear directly from actual suppliers and manufacturers of products we members use! That said, can you tell me more details on some of the reports of your '40 springs being too short? I asked one of your CS guys and he thought it was because the '40 was one of the most heavily modified vehicles and the hangar/shackle placements aren't always uniformly spaced. I asked him if he could tell me the measurements of the springs but couldn't actually measure them either because he was not collocated with the factory.

I'd like to know the virtual eye-to-eye distance (flat distance as the spring sits on the ground on its two eyelets) and the actual curved distance along the length of the spring. If I knew those measurements, I'd have an idea if they would be long enough. Thanks again Miller!

Happy to help! The only specs I have handy are what I listed above on the images. But I can speak to the length topic.

As far as the springs being too short, this is typically a misconception due to the truck being suspended at full droop and the stiffer new spring, (compared to stock), needing weight on it to extend out to its proper location. These leaf springs are made to the correct length and will sit properly IF the correct amount of weight is on them. These are "uprated" leafs vs stock, looking for more constant weight on them.

The bigger contributor to it appearing too short is that most 40's are living the retired life and/or are stock weight. Once installed, and the truck is back on the ground, the shackles appear to be super extended out. There is simply not enough weight on the leaf spring for it to sit in the "butter zone" where its sitting properly. With 7 leafs on these, they really want additional weight on them. Do the process I listed above and remove a leaf to get it to sit down and extend out a bit. Otherwise you are fighting the camber on the leafs and won't have a good ride. It all comes down to weight on the leafs, the more weight the more the camber curve flattens out and eyelets extend out. That eyelet to eyelet measurement will change as weight is applied to or removed from the leaf spring.

Hope this helps!

-Miller

 

[JKIII FJ40]

I also wanted to provide some reference specs for our 40 Series leaf springs along with some tips to make the ride better. See below images of the TOY001B front leaf pack, and TOY002B rear leaf pack.
View attachment 4123821
View attachment 4123822
These are both Single Stage Leaf Springs with a 7 stack of individual springs. These leaf springs are looking for some added weight to be on them with the 7 stack. They are considered a medium load spring looking for to an additional load of 0-220lbs for the front and 0-440lbs for the rear. These will work with both the F Series and B Series engines, although the 2F and 3B engines are a bit heavier, that weight will help. The TOY001B and TOY002B are for the 1960-'80 40 Series. The TOY001B front leaf is also for the 45 Series and for the 1980-'84 42 Series. All other 40 Series in the longer wheel bases will use other part numbers front and rear.

If your 40 is bone stock, no added weight from any accessories, no front winch, just a stock Sunday cruiser, then I would highly recommend removing a leaf from the stacks front and rear for a better ride. Typically the #3 leaf is a good one to start with. Without any additional weight, they will be firm and sit a bit too tall, but again, simply remove a leaf to bring it back down a bit.

My recommended process is to get measurements before and after the suspension install. This data will help you dial in how the vehicle sits.

First, get your Land Cruiser on dead level ground on the current suspension setup and measure from the center of each hub straight up to the bottom edge of each fender. Do this for all 4 corners and record the data.

Second, do your suspension install as the components were sent, don't remove any leafs yet. Once installed, drive the vehicle around the block a bit, hit a bump or two, so everything settles in. Take note how it feels while driving, how it sits, how it reacts, how it handles, etc... Then get back on dead level ground and do the same measurements again. Record the data.

Now, compare the before and after measurements to see how much the vehicle changed, what the rake is (fore and aft), what the list is. You now have numbers you can use to make smart and specific suspension adjustments, like removing leafs. If you do end up removing a leaf go through the same measurement exercise again to see how much did it change, repeat and adjust as necessary.

I do this process every time I fart around with the suspension, and more importantly, every time I add or remove significant weight from the vehicle. This is best when adding/removing permanent accessories like bumpers, winches, etc... It's really smart to see how much the added or subtracted weight changes how the vehicle sits. Follow this process and the data will help you make better decisions for suspension adjustments resulting in a better ride, better weight support, and a better handling safer driving vehicle.

And if you have any other curveballs like an Aqualu alloy tub, Metaltech roll cage, aftermarket tube fenders, run it without the OEM roof, etc... or other mods that affect the axel weights then take that into consideration and rely on the measurement process to adjust suspension.

Again, typically if its a stock "Sunday Cruiser" then you will want to remove a leaf.

I love a good process! It's good to build the discipline to follow and refine a process.

I hope this novel helps! Holler if you have any other questions!

-Miller

thanks for the info, this does help and it looks like I will be pulling a leaf all around.

 

[Augustiron]

Yeah.
No.